Typically, refrigerated display cases require some type of deflector to deflect air into an air louver, or a plurality of deflectors that both deflect and direct airflow. As a result, two or more pieces are required in a discharge air louver, leading to a more difficult and less accurate and repeatable manufacturing process.
FIGS. 1 and 2 illustrate prior art louvers 11, 51 for refrigerated display cases 10, 50. FIG. 1 shows a refrigerated display case 10 having a louver 11 coupled to an insulated wall 12 and an internal wall 14 of the refrigerated display case 10. The louver 11 is positioned in an air passage 16 of the refrigerated display case 10 through which airflow is directed in the direction of arrow 18.
The louver 11 includes a honeycomb portion 20 and a deflector 22. The honeycomb portion 20 includes a plurality of channels 24 positioned to control the direction of the airflow out of the air passage 16. The deflector 22 is positioned to deflect the airflow as it flows in the direction of arrow 18 toward the honeycomb portion 20. Specifically, the deflector 22 includes a series of linear segments 26 positioned at an angle with respect to one another to impart a specific velocity profile 28 to the airflow passing through the louver 11. As shown in FIG. 1, the combination of the deflector 22 and the honeycomb portion 20 produces an air curtain with a highly variable velocity profile 28. In addition, tolerance stack-ups when manufacturing and/or assembling the deflector 22 and the honeycomb portion 20 may not allow for accurate and repeatable results when manufacturing the refrigerated display case 10.
FIG. 2 shows another prior art refrigerated display case 50 having a louver 51 positioned within an air passage 56 defined by an insulated wall 52 and an internal wall 54. Airflow in the air passage 56 generally flows toward the louver 51 in the direction of arrow 58. The louver 51 is constructed from individual nested turning vanes 60 that define a plurality of channels 61 therebetween. Each turning vane 60 includes a vertical portion 62 and a horizontal portion 64 to control the direction of the airflow. The spacing between adjacent vanes 60 controls the size of the channels 61 therebetween, and causes some channels 61 to receive a greater portion of the airflow than others. Accordingly, the spacing between adjacent vanes 60 imparts a specific velocity profile 68 to the airflow passing through the louver 51. As shown in FIG. 2, the louver 51 produces a stepped velocity profile 68. The individual nested vanes 60 of the louver 51 complicate the production and assembly of the louver 51.